Field of the Invention
The present invention relates to downhole packers. More particularly, the present invention relates to a downhole packer with feed-through connections for communication conduits and a method for pressure testing the connections.
Field of the Invention
Downhole packers are typically used to seal an annular area formed between two co-axially disposed tubulars within a wellbore. For example, downhole packers may seal an annulus formed between production tubing disposed within well bore casing. Alternatively, packers may seal an annulus between the outside of a tubular and an unlined borehole. Routine uses of packers include the protection of casing from pressure, both well and stimulation pressures, as well as the protection of the wellbore casing from corrosive fluids. Other common uses include the isolation of formations or leaks within a well bore casing or multiple producing zones, thereby preventing the migration of fluid between zones. Packers may also be used to hold kill fluids or treating fluids within the casing annulus.
Conventional packers typically comprise a resilient sealing element located between first and second retaining rings. The sealing element is typically a synthetic rubber composite which can be compressed by the retaining rings to expand radially outward into contact with an inner surface of a well casing there-around. The compression and expansion of the sealing element seals the annular area by preventing the flow or passage of fluid across the expanded sealing element.
Conventional packers are typically run into a wellbore within a string of tubulars and anchored in the wellbore using mechanical compression setting tools or fluid pressure devices. Conventional packers are also typically installed using cement or other materials pumped into an inflatable sealing element.
During the production of a well, downhole devices are often controlled or otherwise in communication with above-ground equipment. For example, a control panel above the earth""s surface may direct a downhole valve to open or close, a sleeve to shift, or a motor to turn on or off. Data is also collected through the use of downhole devices and transmitted to the surface. For example, data may include pressure readings, temperature readings, flowing velocities, or flow rates. Data sent to and from the surface may be transmitted through a control line such as an electrical wire, fiber optic, or hydraulic conduit.
Control lines connecting the surface equipment and the downhole devices are typically placed in the annulus between the well casing and the production tubing. For devices above a packer this is easily accomplished since the annulus is unobstructed. However, devices below a packer present a challenge since the annulus is sealed off. Packers of the prior art have provided for control lines to pass through the sealing element. One disadvantage associated with running the control lines through element is that the mechanical integrity of the sealing element is compromised. Another disadvantage is that an effective seal between the sealing element and the control lines traversing there-through is difficult to establish and even more difficult to maintain.
Therefore, packers have recently provided for the control lines to pass longitudinally there-through. However, one disadvantage associated with packers of this type is pressure testing each and every connection disposed within the packer. Pressure testing each and every connection consumes valuable time prior to running the packer down the hole. Another disadvantage arises in these packers upon the retrieval of the packer from the well bore. Upon retrieval of the packer from the well bore, the control lines are simply stretched until they break. There is no way to determine how much force is required to break the control lines, and there is no way to determine where the control line will physically break.
Furthermore, retrievable packers typically have a release mechanism disposed within a larger bore of a multi-bore packer because of the weight of the attached tubing string. The cross sectional area of a small bore is simply too small to handle the weight of an attached tubing string. One problem associated with having the release mechanism disposed within the large bore is that the larger bore is often in communication with the production tubing. Often times, the release mechanism becomes jammed or stuck due to an accumulation around the release mechanism of waxy paraffins from within the production fluid, making the packer difficult or near impossible to release.
Therefore, there is a need for a downhole packer having a release mechanism disposed within a small bore that can withstand the weight of the attached tubing string. There is also a need for a packer with internal communication conduits having a cutting mechanism for controllably severing the control lines disposed there-through. There is further a need for a packer having one or more internal communication conduits having one test port to pressure test each connection of the packer thereby saving time and resources prior to running the packer down the hole.
In one aspect, a packer is provided having a release mechanism disposed within a small bore that can withstand the weight of the attached tubing string. In one aspect, the packer comprises a body having one or more conduits formed there-through; a lock body disposed on a first end of the body; a collapsible member threadably engaged to the body at a first end and shouldered against the lock body at a second end; and a slideable member disposed within the collapsible member. In another aspect, the packer comprises a lock body disposed on a first end of the body, wherein the lock body comprises a recessed groove formed in an inner surface thereof; an expandable ring disposed within the recessed groove, wherein the expandable ring comprises concentric grooves disposed on an inner surface thereof which matably engage concentric grooves disposed about an outer surface of the body; a releasable collar at least partially disposed about the expandable ring; and a slideable sleeve at least partially disposed about the releasable collar.
A packer is also provided with internal communication conduits having a cutting mechanism for controllably severing the control lines disposed therethrough. In one aspect, the packer comprises a body having one or more conduits formed there-through, wherein the one or more conduits comprises an enlarged first end; and a cutting member disposed with the enlarged first end. Movement of the body compresses the cutting member into a control line disposed within the conduit thereby controllably severing the control line.
A packer is further provided with one or more internal communication conduits having one test port to pressure test each connection of the packer thereby saving time and manpower. In one aspect, the packer comprises a body having one or more conduits formed there-through; a chamber disposed within the body, wherein the chamber is in fluid communication with each of the one or more conduits; and an aperture for pressurizing the chamber. Pressurized fluid flows in a first direction through a first conduit to the chamber and flows in a second direction from the fluid chamber through each conduit.
In addition, a method for retrieving a packer from a well bore is provided. In one aspect, the method comprises attaching a retrieval tool to a body, the body comprising one or more conduits formed there-through; a lock body disposed on a first end of the body, wherein the lock body comprises a recessed groove formed in an inner surface thereof; a ring disposed within the recessed groove, wherein the ring comprises concentric grooves disposed on an inner surface thereof which matably engage concentric grooves disposed about an outer surface of the body; a collar at least partially disposed about the ring; and a sleeve at least partially disposed about the collar; moving the sleeve from a first position to a second position using the retrieval tool; releasing the collar; and then expanding the ring. In another aspect, the method comprises attaching a retrieval tool to a body, wherein the body has one or more conduits formed there-through; a lock body disposed on a first end of the body; a collapsible member threadably engaged to the body at a first end and shouldered against the lock body at a second end; and a slideable member disposed within the collapsible member. The retrival tool is used to move the slideable member from a first position to a second position thereby disengaging the collapsible member from the lock body. Movement of the slideable member allows the collapsible member to collapse inwardly and release the packer.
Further, a method of severing a control line in a well bore is provided. The method comprises releasing a body, the body comprising: one or more conduits formed there-through, wherein the one or more conduits comprises an enlarged first end; one or more control lines disposed within the one or more conduits; and a cutting member disposed with the enlarged first end; and compressing the cutting member. The cutting member has a sharp edge disposed thereto that controllably severs the control lines disposed through the conduits.
Still further, a method of pressure testing conduits of a packer is provided. In one aspect, the packer comprises flowing a fluid into a body, wherein the body has one or more conduits formed there-through, wherein the one or more conduits comprises a seal mandrel disposed therein and an annular cavity formed between an outer surface of the seal mandrel and an inner surface of the body; and a chamber disposed within the body, wherein the chamber is in fluid communication with the annular cavities. The chamber acts as a manifold for pressure testing the one or more conduits. The pressurized fluid flows in a first direction through a first annular cavity to the chamber and flows in a second direction from the fluid chamber through each annular cavity.